What Is Basement Underpinning?

For people living in dense urban centres, there are limited options when it comes to expanding your living space. You can expand horizontally by adding a backroom to the first floor of your home, however you will have to pass through various variance hurdles related to zoning.

An increasingly popular option for people living in cities is to look beneath their feet. The idea may seem inconceivable because of the difficulty associated with building downwards, and is generally an unheard of option for the most part.

However, the renovation and construction industry has two solutions for this problem: underpinning and bench-pinning.

During the construction of the house, contractors don’t often have an easy time with digging underground, so it’s understandable to say that the job is far more difficult with a house sitting on top of the dig site. Another added difficulty is removing material around the foundation without disrupting the integrity of your home.

In dense urban areas where homes are close to each other, it may be possible to disturb the stability of your neighbour’s home if the contractor isn’t careful. Expertise is going to be key here, as well as the necessary city permits.

Bench-Pinning Works for Large Basements

Bench-pinning is faster and cheaper, but the trade-off also shrinks the basement’s width while you’re gaining depth. It works by adding to the existing structure by lining the perimeter with concrete to enforce the sides. The general rule of thumb is reduce the width of your basement by a foot when you extend the floor by a foot (it’s a 1:1 ratio). As you can see, for smaller basements, you’re quickly going to lose space as soon as you gain any noticeable headroom.

Underpinning is the Better Option

Underpinning works on small sections of the foundation at a time, leaving the remaining sections intact to hold up the upper floors of the home. Sectioning off the foundation means that the process is slow, and the slower things go, the more expensive the final bill.

The renovation starts with excavation past the foot of the basement walls. New footings are poured in to form the new walls. Inner walls are established first, and the work extends outwards, while the floors are the last to go in.

Carefully evaluate your budget and your options before beginning any sort of renovations, especially when considering expanding your home. If you find that it’s within budget, consult with a professional to see what can be done to improve your home!